"We don't restrict selling it as a part of a bigger distribution like
ubuntu and stuff like that. What we are restricting is that you can't
sell just teeworlds and take money except for the media cost. This
license was discussed in great length and input were taken from some
fedora legal guy (can't remember the name). The SIL Open Font Licence
contains a similar statement and is considered to be free by the FSF guys."

I hope this clears things up a bit.
Jack Coulter
Charles Plessy wrote:

That's the zlib license (http://www.gzip.org/zlib/zlib_license.html)
with an extra clause forbidding some kind of commercial usage
("Neither this software nor any of its individual components, in
original or modified versions, may be sold by itself"). I'm not really
sure that it is DFSG-compliant. I'm CCing debian-legal to get other
opinions on that.

That is a similar clause to the one in the Open Font Library. Fonts
using the OFL have been accepted into Debian, so presumably the
ftpmasters would accept this licence.

Hi Paul
If yes, please post a mail on debian-devel-announce@lists.debian.org,
because I bet that many maintainers of non-free packages will be happy
to make an upload to main.
More seriously, this is obviously non-free, and would make serious
difficulties for the distributors of Debian CDs. Consider that even
software that allow redistibution for a fee but disallow profit are not
accepted in main.
Jack, I strongly recommend to contact Upstream and to expose some clear
arguments in a kind and friendly style. "No commercial use" was invented
in a past were people did not try to live from free software. Upstream
may be sensitive to this, to the problem of redistribution, and might
accept to relicense.
Have a nice day,